New Century and Integrity Plus Blog

What is a Moderate Consequence Area?

Posted by Sarah on Jul 27, 2016 11:00:00 AM

Pipeline regulations are changing, and Integrity Plus and New Century Software are here to help you stay ahead of the game. One of the most recent proposed changes has already been implemented into our Gas HCA Analyst application, so you can get a jumpstart on evaluating the impacts of the proposed change to your integrity management programs and budgets.

On March 15, 2016, PHMSA published a Notice of Proposed Rule Making (NPRM) proposing several changes to safety regulations regarding onshore gas transmission and gathering lines, integrity management (IM) requirements, and non-IM requirements. Among the non-IM requirements was a proposed definition for moderate consequence areas (MCAs).

A moderate consequence area is defined in the proposed rule as “an onshore area that is within a potential impact circle, as defined in §192.903, containing five (5) or more buildings intended for human occupancy, an occupied site, or a right-of-way for a designated interstate, freeway, expressway, and other principal 4-lane arterial roadway as defined in the Federal Highway Administration’s Highway Functional Classification Concepts, Criteria and Procedures, and does not meet the definition of high consequence area, as defined in §192.903.” The “occupied site” concept is similar to that of identified sites used for determining high consequence areas (HCAs), except with a lower occupancy threshold. This additional definition, along with the arterial roadway rights-of-way requirements, will increase the data required to complete HCA and MCA analyses.

The need for moderate consequence areas is derived from the fact that just because an area is not “high consequence” does not mean that there aren’t potentially significant consequences should an incident occur. As pointed out in the NPRM, “devastating incidents have occurred outside of HCAs in rural areas where populations are sparse, but present.” Incidents in rural, non-HCA areas such as one in 2000 in Carlsbad, NM that killed 12 campers, or the 2012 Sissonville, WV incident that destroyed three houses and closed a major Interstate highway, have driven the attention toward requiring some integrity management activities outside of HCA areas.

The key takeaway is that PHMSA is proposing to expand certain IM requirements beyond HCAs by creating the new MCA classification. MCAs would be used to define the subset of non-HCA pipeline locations where periodic integrity assessments are required, where material documentation verification is required, and where MAOP verification is required. New Century Software, with input from New Century’s Integrity Plus experts, has added support for some of these requirements to Gas HCA Analyst 5.0.1.


For more information on MCAs and the NPRM, contact our Integrity Management experts, and learn how you can start calculating MCAs with Gas HCA Analyst 5.0!

Topics: PHMSA, HCA, 49 CRF 192, Gas HCA Analyst, MCA, GHCA

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